Fix ci cleanup in docker image (pip uninstall not works without pythonpath export and do not remove INSTALLDIR but INSTALLDIR/lib/site-package/*). Various fixes

Merge branch '46-add-python3-x-support' into 29-hysop-with-tasks

Improve tasks operators and graph handle. Improve inter-tasks automatic inserting of RedistributeInter. Better profiling  and task profiler report (statistics over ranks). Add nested problems better graph creation and interaction across levels. Fix overlapping bridges and redistributes. Fix io_utils FS type process safety (deadlock issue with tasks)

Merge branch '46-add-python3-x-support' of gricad-gitlab.univ-grenoble-alpes.fr:particle_methods/hysop into 46-add-python3-x-support

Merge branch '46-add-python3-x-support' of gricad-gitlab.univ-grenoble-alpes.fr:particle_methods/hysop into 46-add-python3-x-support